Well, crawl under it and poke the bottom of the center muffler, then check the rear muffler. The center muffler section is available as a bolt in component from Ansa that looks identical to OEM. In fact, they probably make this part for DC. They also make the rear section, and depending on what kind of deal you get they are around $150 apiece.
The only difference between OEM and the ANSA components is you'll have a joint between the center section and rear section. The OEM system is one piece from the converter back, but the DB replacements are two piece like the Ansa.
I would recommend you go with either OEM replacement parts or Ansa through the aftermarket. Mercedes exhaust systems are very efficient - a conbination of excellent sound attenuation and low back pressure, and the ancecdotal evidence I have from guys who had muffler shops fabricate exhaust system with "hot rod" parts yielded a louder and poorer performing car.